Incandescent lamps (more commonly known as “light bulbs”) dominate residential lighting markets due to their relatively low cost and unparalleled accessibility. The glass-encased metal filament, which is electrically heated to generate light, is typically supplied with electrical current by wire feed-through terminals embedded within the bulb's threaded metal base. Most light bulbs are designed to thread into a light socket (also known as an “Edison base”) which provides mechanical support for the bulb and connects the current supply to the bulb's electrical terminals. Other artificial lighting lamps, such as fluorescent, halogen, high-intensity discharge (HID), and even light-emitting diode (LED) lamps, are available with bases that are compatible with standard Edison light sockets.
The light socket, in turn, is often part of a light base which is attached to, or designed for attachment to, a support structure. Historically, light bases are powered through a cable-to-cable connection with an electrical utility system. The most common connectors have a single input-connection feature and a single output-connection feature, each of which is secured by a screw or other threaded fastening means. Some specialized connectors provide several entrance features that operate as input/output connections. Screw-type attaching means, however, require separate tools and additional labor time to complete each electrical connection, and are prone to improper installation which can lead to a defective connection.
The connector is typically designed as a “safety box” to prevent inadvertent handling of live electrical parts. For some light bases, the connection from the electrical grid is via a small sheet-metal component known as a “blade” and not by wire. This configuration allows the connector to energize components with different geometries in a reduced space. Due to cost and packaging constraints, however, some light bases provide less space between the socket and the connector box. Nevertheless, the connector must still provide all of the requisite cabling and connections inside of this limited packaging space.